A Level Biology Practice Exam

What is the role of carbonic anhydrase in the body?

1. To convert glucose into energy

2. To catalyze the formation of carbonic acid from carbon dioxide and water

3. To aid in muscle contraction

4. To regulate body temperature

The correct answer is: To catalyze the formation of carbonic acid from carbon dioxide and water

The role of carbonic anhydrase in the body is to catalyze the formation of carbonic acid from carbon dioxide and water. This enzyme is crucial in the regulation of blood pH and maintaining acid-base balance. When carbon dioxide is produced during cellular respiration, it diffuses into the blood and reacts with water, a reaction that carbonic anhydrase significantly speeds up. This reaction leads to the formation of carbonic acid, which can dissociate into bicarbonate and hydrogen ions. The reversible nature of this reaction helps in the transport of carbon dioxide from tissues to the lungs, where it can be expelled from the body. The other options are unrelated to the specific function of carbonic anhydrase. For instance, the process of converting glucose into energy occurs primarily through pathways like glycolysis and cellular respiration, which involve a different set of enzymes. Muscle contraction involves proteins such as actin and myosin, and regulatory mechanisms often include calcium ions but not carbonic anhydrase. Lastly, the regulation of body temperature is controlled through various physiological mechanisms such as sweating and shivering, also independent of the action of carbonic anhydrase.